Efficient Degradation of Dye Wasterwater by Catalytic Ozonation Reactive Ceramic Membrane with Facile Spraying of Nano Ti-Mn Oxides: A Pilot Scale Attempt

Abstract

The traditional treatments of dye wastewater exist obvious drawbacks of low efficiency but high energy consumption. In this paper, based on the concept of combining degradation and separation, an integrated process of Ti-Mn oxides catalytic ozonation and ceramic membranes (CM) was proposed to degrade dye wastewater. Specifically, TiO2/MnO2 hybrid catalysts were loaded on the surface of CM with a spraying method to prepare a reactive ceramic membrane (TiO2/MnO2-CM). Subsequently, the degradation efficiency and permeate flux of the TiO2/MnO2-CM wastewater treatment system on Rhodamine B (RhB) were investigated. The SEM results illustrated that the catalyst was successfully loaded on the surface of CM. Additionally, the degradation efficiency of RhB was 100% in 40 min under the conditions of catalyst spray layers 12, ozone concentration 2.5 g/cm3, and initial concentration of RhB 20 mg/L. Meanwhile, the permeate flux of TiO2/γ-MnO2-CM was as high as 125.399 kg/ (m2·h). Supplementarily, the study revealed that TiO2/γ-MnO2-CM could increase the concentration of ozone in water and catalyze ozone to produce more •OH (hydroxyl radicals). Eventually, the catalytic ozonation TiO2/γ-MnO2-CM device was scaled up, which treated 96 L RhB with a degradation efficiency of 100% in 50 min. The work gives a solid foundation for the industrial application of reactive ceramic membranes in water or wastewater treatment.

Keywords: Catalytic ozonation, Ti-Mn oxides, Reactive ceramic membrane, Dye wastewater, Reactor scale-up